Atmospheric pressure glow discharge in air and its application to surface modification of PP nonwovens

Glow discharge (GD) in air at atmospheric pressure would open up broader prospect than glow discharge in gas other than air at atmospheric pressure or glow discharge in low-pressure air. In this paper, the GD and a filamentary discharge (FD) in a 3 mm air gap were generated using a high frequency power source and dielectric barrier controlled electrodes. The irradiance characteristics of the GD were compared with those of the FD. In addition, the GD and the FD in air at atmospheric pressure treated PP nonwovens respectively, and the wettability of the treated materials characterized by contact angle of static distilled water dropped on nonwovens surface was measured. It was found that the transition from FD to GD in a 3 mm air gap was achieved under certain conditions. The polypropylene (PP) nonwovens were destroyed when treated by the FD, but not by the GD. The contact angle of the static distilled water dropped on the treated decreased to 60° from 120°, which was that on the untreated nonwovens.